IMPG2-associated unilateral adult onset vitelliform macular dystrophy

PURPOSE: To present a case of unilateral IMPG2-associated adult onset vitelliform macular dystrophy (AVMD). OBSERVATIONS: A 68 year-old female presented with best corrected visual acuity (BCVA) of 20/20 and 20/40 for the right and left eye respectively. The patient had a left subfoveal yellow lesion on dilated fundus examination. Optical coherence tomography showed hyper-reflective material accumulation below the fovea in the left eye only. The patient was followed for 10 years with stable BCVA, and evolution of the subretinal vitelliform lesion to a “vitelliruptive” stage. The right eye did not develop vitelliform lesion. Genetic testing identified a heterozygous likely disease-causing variant in IMPG2; c.3423–7_3423-4del. CONCLUSIONS AND IMPORTANCE: This is the first report of unilateral AVMD associated with IMPG2, expanding the phenotypic spectrum of IMPG2 retinopathy. We provide further evidence that IMPG2 variants can cause both autosomal recessive rod-cone dystrophy and autosomal dominant AVMD, with implications for patient counselling.